Xanthogranulomatous pyelonephritis: a focus on microbiological and antibiotic resistance profiles

Abstract

Background Xanthogranulomatous pyelonephritis (XGP) is an inflammatory condition of the kidney and its treatment most often involves a combination of antibiotics and nephrectomy. This study aimed to define the clinical features and management of XGP, focusing on microbiological aspects and antibiotic therapy. Methods We performed a retrospective study of 27 cases of XGP diagnosed between January 2001 and January 2020 to analyse their clinical and management characteristics. In addition, a literature review was conducted of XGP case series covering the period from 2000–2020. We searched PubMed for case series through April 2020 without language restrictions. Studies reporting case series of XGP (more than ten cases) were included if they were relevant to this study. Results Twenty-seven patients were diagnosed with XGP, and 26 of them were histologically proven to have XGP. A total of 81.5% of the patients were female and the mean age was 59.6 years (SD 19.2). The most frequent symptoms were flank pain (70.4%) and fever (59.3%), while 77.8% of patients had renal stones. Proteus mirabilis was detected in the urine culture in 18.5% of patients, followed by detection of Escherichia coli in 14.8% of patients. The computed tomography (CT) findings included perirenal (29.6%) or pararenal (29.6%) involvement in the majority of patients. Twenty-six patients underwent nephrectomy. Piperacillin/tazobactam and ceftriaxone were the most commonly prescribed antibiotics for treatment. The reported piperacillin/tazobactam and ceftriaxone resistance rates were 14.3% and 16.6%, respectively. Twenty-six case series were included in the literature review, reporting 693 cases in total. Conclusion We found well-established characteristics of XGP patients among series in terms of previous history, clinical, laboratory and imaging findings, and operative and postoperative outcomes. It is important to know the clinical presentation and potential severity of XGP, as well as the most frequently involved microorganisms and their antibiotic resistance profiles, to select the most appropriate antibiotic therapy.

Case report: Localized xanthogranulomatous pyelonephritis in children: A case report and literature review

“…Such abnormal laboratory findings of XGP have been reported: leukocytosis, thrombocytosis, anemia, elevated inflammatory markers (ESR, CRP), and positive urine cultures ( 10 , 11 ). According to relevant studies, for over half of the patients (both adults and children) with positive urine cultures, the major bacteria in urine cultures were Proteus vulgaris and Escherichia coli , with the difference being presence of Gram-positive bacteria in urine cultures ( 12 , 13 ). For the patient in the present case, both the preoperative blood and urine cultures were negative.…”

Malakoplakia and xanthogranulomatous pyelonephritis treated with nephrectomy

“…[ 8 ] The most common organism involved is Proteus mirabilis (18.5%), followed by E. coli (14.8%). [ 9 ] XGP affects mostly women (a women:men ratio up to 6:1). [ 10 ] It usually presents in the fourth or fifth decade of life, however it can be present at any age.…”

Xanthogranulomatous Pyelonephritis: A Narrative Review with Current Perspectives on Diagnostic Imaging and Management, Including Interventional Radiology Techniques

“…The overall antibiotic resistance profile was also explored in this case series which showed resistance to Quinolones (14.3%), Amoxicillin/Clavulanic Acid (12.5%), Piperacillin/Tazobactam (14.3%), Cegtriaxone (16.6%), Fosfomycin (33.3%) and Trimethoprim/Sulfamethoxazole (33.3%). 33 …”

“…A case series of 27 XGP patients showed Piperacillin/Tazobactam (TZP) was the most commonly prescribed antibiotic combination (48.1% of patients), followed by third-generation cephalosporins (18.5%). 33 This approach also decreases the risk of post-surgical complications such as fistulae and impaired wound healing. 60 …”

“…A case series of 27 XGP patients showed Piperacillin/Tazobactam (TZP) was the most commonly prescribed antibiotic combination (48.1% of patients), followed by third-generation cephalosporins (18.5%). 33 This approach also decreases the risk of post-surgical complications such as fistulae and impaired wound healing. 60 Our group recently described a rare complication of XGP, namely extrusion of renal calculi from the renal collecting system into the retroperitoneum with psoas abscess formation in a 64-year-old female.…”